R2-D2 comes from the peaceful world of Naboo, where he and a team of astromechs served the elected monarch aboard her Royal Starship. When the greedy Trade Federation invaded Naboo, Queen Amidala rushed away from her world and ran afoul of a blockade. When the Royal Starship sustained damage to its shields, it was R2-D2 who repaired the ship, allowing it to escape into hyperspace. The droid used his magnetized rollers to cling tenaciously to the chromed surface of the ship while deadly turbolaser blasts rained overhead. For his courage, Artoo was personally thanked and recognized by Queen Amidala.

To complete further repairs, the Royal Starship set down on the barren Outer Rim world of Tatooine. Artoo-Detoo accompanied Jedi Master Qui-Gon Jinn and Royal Handmaiden Padmé Naberrie to the port city of Mos Espa to gather spare parts. Artoo carried the technical details for the necessary parts. While waiting out a sandstorm in a local hovel, Artoo-Detoo met the homemade protocol droid C-3PO, and struck up a friendship that would eventually last decades.

Artoo later returned to Naboo with the Queen. He served as onboard astromech to Anakin Skywalker, a young rookie pilot who, despite not being authorized to do so, flew an N-1 starfighter into the Battle of Naboo.

Artoo would be reunited with Anakin a decade later. The little droid continued to loyaly serve Amidala, who was no longer Queen, but now Senator of Naboo. The droid acted as a little bodyguard, using his scanners to seek out any danger that might befall Padmé. His laser field sensors failed to detect a deadly kouhun attack against a sleeping Padmé, but Anakin's heightened Jedi awareness did. He was able to kill the poisonous creatures, but the Jedi weren't able to determine who wanted Padmé dead.

Amidala left for Naboo, to hide while the Jedi investigated. Artoo stayed by her side as she voyaged to Tatooine, where he was reunited with C-3PO, who again became Anakin's property. They all went to Geonosis, and as Padmé and Anakin wandered into a dangerous Geonosian droid factory, Artoo and Threepio followed. Artoo again came to the rescue, using his anti-grav boosters to fly to Amidala's aid and his computer interface to stop a deadly downpour of molten metal from killing the Senator. He even helped reassemble C-3PO after a decapitating tangle with droid factory machinery.

Years later, Artoo and Threepio would find themselves in the service of the Royal House of Alderaan. The influential family of nobles had secret ties to the burgeoning Rebel Alliance. While intercepting transmissions from Rebel spies, the Organa consular ship was suddenly attacked by an Imperial Star Destroyer laying in wait. The transmission carried information vital to the Rebellion -- the complete technical read-outs of the Empire's latest weapon of mass-destruction, the Death Star battle station. Unable to deliver the plans to Viceroy Bail Organa, Leia Organa instead hid them in Artoo's memory systems. She also tasked Artoo to continue her other mission, that of contacting the long-lost Jedi Knight and Republic General, Obi-Wan Kenobi.

Artoo commandeered an escape pod, and rocketed away from the captured consular ship, all the while dragging along his bewildered counterpart, Threepio. The pod crashlanded on Tatooine. There, the droids were taken captive by Jawa traders, and sold to moisture farmer Owen Lars and his nephew Luke Skywalker. Determined to complete his mission, Artoo ran away in the middle of the night, leaving Threepio and Luke to search for him the next morning.

Threepio and Luke eventually found Artoo, as well as Obi-Wan Kenobi. This started an incredible chain of events that culminated in the Battle of Yavin. Artoo and Threepio were crucial in assisting Luke spearhead a rescue mission to free Princess Leia from the heart of the gargantuan Death Star. Both droids navigated the complex Imperial computer system to provide the rescuers with timely assistance and status updates.

Once Artoo returned to the Rebel base with the newly liberated Princess Leia, Alliance technicians downloaded the Death Star schematics. From these, they were able to pinpoint a flaw in the station's design that could be exploited for explosive results. A small thermal exhaust port allowed access to the Death Star's sensitive reactor core. If hit with a precise proton torpedo volley, the entire station could be destroyed. The Alliance launched all available starfighters in an attack on the station. Luke Skywalker piloted an X-wing fighter and R2-D2 served as his on-board astromech, much like he did for Luke's father a generation earlier. Although Artoo sustained some damage in the attack, Luke successfully destroyed the station. Artoo was refurbished in time for the celebration of the Rebel victory.

Threepio and Artoo continued to be mainstays with the core group of Rebel heroes. Despite their constant disputes -- like the time Artoo took Threepio's complaining of Hoth's subzero temperature as an invitation to turn the heat up in Princess Leia's quarters, thus flooding her compartment with melted ice -- the two remained friends.

During the evacuation from Hoth, Threepio and Artoo were separated. Artoo flew with Luke to the mysterious planet of Dagobah, where Luke would receive training from the enigmatic Jedi Master, Yoda. Artoo was witness to Luke's growing skill and power, as the young Tatooine farmboy continued on his path to Jedi Knighthood.

When Luke's friends fell into an Imperial trap on Bespin's Cloud City, Artoo accompanied the young Jedi to the floating metropolis. There, he became separated from Luke, but he did find C-3PO, Princess Leia, and Chewbacca. The Rebel heroes were worse for wear, especially Threepio, who had been blasted apart by an Imperial stormtrooper. While escaping Bespin, Artoo helped reassemble his friend.

During a daring mission to rescue a captive Han Solo from the loathsome gangster Jabba the Hutt, Threepio and Artoo were sent into the Hutt's palace on Tatooine. There, they became the gristly crime lord's property. Artoo served as a waiter, distributing drinks aboard Jabba's sail barge. Little did any of the criminal dregs suspect that Artoo carried in him Luke Skywalker's lightsaber, which he launched to the unarmed Jedi. Supplied with his weapon, Luke subdued Jabba's minions and freed his captive friends.

Shortly thereafter, Artoo accompanied the Rebel strike force that was sent to knock out the Imperial shield generator on Endor. The generator protected the half-completed second Death Star high in orbit. Artoo attempted to bypass the high security lock sealing the Imperial generator complex, but was shot by a stormtrooper before he could complete the task. Fortunately, the Rebels were able to make their way into the complex, and destroyed the generator. Artoo-Detoo was repaired in time to witness the destruction of the second Death Star.